Wednesday 15 January 2014 13.05 EST
First published on Wednesday 15 January 2014 13.05 EST

Laurie Penny is wrong to characterise the new approach to the provision of internet filters – to make them more readily available to parents who want to protect their children from age-inappropriate content – as a Tory plot (Cameron's "porn" filter is a mask for censorship creep, 3 January).

I was closely involved in many of the discussions and negotiations that led to the UK's "big four" internet service providers taking this action. It is true that the prime minister strongly supports the greater use of filters, but so do the Labour party and a number of civil society and children's organisations.

Penny says: "In the name of protecting children from a tide of raunchy videos, a terrifying precedent is being set for state control of the digital commons." No. This is all about making it a great deal easier for parents to use filters if they want them. The decision about whether or not to do so is entirely in their hands, not the state's. Mobile phone companies have had default filters in place since 2005; ISPs are just catching up. To suggest a link with "terrifying" state-sponsored censorship requires a huge leap of imagination.

Penny conjures up a scene where an imaginary telesales worker rings up a new customer and "wants to know – do you want to be able to see hardcore pornography?" This simply will not happen. Every ISP that offers filters will do so via a series of mouse clicks against a range of given categories.

"Every argument we have heard from politicians in favour of this internet filter has been about pornography," Penny says. She has not been paying attention. I once had the misfortune to alight upon a website featuring a video of two men being killed and dismembered by a chainsaw. I wonder how a nine-year-old would sleep after being exposed to that? How about images of woman-hating violence? Videos of three men simultaneously beating and raping someone is not my idea of "raunchy". Which parent would not do whatever they could to keep that off their kids' screens? It may offend some dudes in Silicon Valley to talk like this, but that's not the first place most of us turn for advice on good parenting.

Are the filters the ISPs use perfect? No. Very few bits of software are. Will the filters get better? Yes. Sites that provide useful information to young people about sexual health are a prime example of the kind that could be unintentionally restricted. But it's not a reason for suggesting filters should never be used: such errors can be easily rectified.

I very much hope no parent will use filters in an oppressive way to deny their children access to the riches of the internet; but, equally, it does not follow that every parent should feel obliged to provide unrestricted access to all its horrors.